Exhibit 10.43(b)


                                AMENDMENT NO. 1
                                      TO
                                 IRU AGREEMENT

THIS AMENDMENT NO.1 to IRU Agreement (this "Amendment") is made and entered into
as of this 18/th/ day of April, 2001 (the "Effective Date") by and between Qwest
Communications Corporation ("Qwest") and Pac-West Telecomm, Inc. ("Customer").
Qwest and Customer are sometimes collectively referred to herein as the
"Parties."

WHEREAS, Qwest and Customer entered into that certain IRU Agreement effective as
of June 30, 2000 (the "Agreement"); and

WHEREAS, the Parties desire to modify the Agreement to reflect new payment terms
for the IRU Fee, as more particularly described below.

NOW, THEREFORE, in consideration of the foregoing and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
Parties agree as follows:

1.   The Agreement is hereby amended so as to provide that, notwithstanding
     anything to the contrary in Section 3.1 or elsewhere in the Agreement,
     Customer shall pay to Qwest the balance due of the IRU Fee ($17,239,841) on
     May 15, 2002.

2.   The Agreement and this Amendment constitute the complete agreement of the
     Parties concerning the subject matter hereof, and supersede any prior
     written or verbal statements, representations, and agreements concerning
     the subject matter hereof. Except as expressly modified by this Amendment,
     the Agreement is and will remain in full force and effect in accordance
     with its terms and constitutes the legal and binding obligations of the
     Parties.

IN WITNESS WHEREOF, an authorized representative of each Party has executed this
Amendment as of the dates set forth below.

QWEST COMMUNICATIONS CORPORATION        PAC-WEST TELECOMM, INC.

By:    /s/ Gregory M. Casey             By:    /s/ Richard E Brysan
       -------------------------               -----------------------
Name:  Gregory M. Casey                 Name:  Richard E Brysan
       -------------------------               ----------------------
Title: V.P. Wholesale mets              Title: CFO
       -------------------------               ---------------------
Date:    5/14/01                        Date:    5/14/2001
       -------------------------               ---------------------

*P&OM Director: ________________

Date:   5/15/01
      --------------------------

*This Agreement shall not be binding upon Qwest until countersigned by the
P&OM Director and Executive Vice President, Wholesale Markets (or an authorized
designee) for Qwest.

May 15, 2001

   LKB
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QWEST/FIRST AMENDMENT

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                         CONFIDENTIAL AND PROPRIETARY


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